Add Reddit monitoring bot — backend, frontend, and Docker config

Python/FastAPI backend with PostgreSQL for collecting Reddit data via
public .json endpoints. React/Vite dashboard for analytics. Docker Compose
setup with API and worker services connecting to shared PostgreSQL.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/schemas/author.py

@@ -0,0 +1,13 @@
+from datetime import datetime
+from pydantic import BaseModel
+
+
+class AuthorResponse(BaseModel):
+    id: int
+    username: str
+    first_seen_at: datetime
+    last_seen_at: datetime
+    total_posts: int
+    total_comments: int
+
+    model_config = {"from_attributes": True}